Air quality in Buenos Aires Province, Argentina

Studies of different gaseous contaminants and particulate matter were made in several cities of the Buenos Aires Province in Argentina. These cities have noticeable differences in relation to the number of inhabitants, vehicular density, industrial activities, etc. They are La Plata, Bahía Blanca, Mar del Plata, Pergamino and San Nicolás, among other towns. In each city, continuous monitoring equipment with electrochemical sensor technology was installed, in order to determine the NOx, CO, HC, SO2 and O3 concentration. The particulate matter samples were picked up using high volume equipment and daily concentrations corresponding to total suspended solids (PM) were determined by a gravimetric method. The particles were characterized by optical microscopy, scanning electron microscopy (SEM) and electron diffraction analysis X-ray (EDAX). The results obtained showed a direct relationship between the type and quantity of the present particles and the general characteristics of the towns. The present study is part of the research project "Study of the Air Quality in Buenos Aires Province", financially supported by the National Agency of Scientific and Technological Promotion, Argentina.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Ciencias Aplicada

Air quality in Buenos Aires Province, Argentina

Studies of different gaseous contaminants and particulate matter were made in several cities of the Buenos Aires Province in Argentina. These cities have noticeable differences in relation to the number of inhabitants, vehicular density, industrial activities, etc. They are La Plata, Bahía Blanca, Mar del Plata, Pergamino and San Nicolás, among other towns. In each city, continuous monitoring equipment with electrochemical sensor technology was installed, in order to determine the NOx, CO, HC, SO2 and O3 concentration. The particulate matter samples were picked up using high volume equipment and daily concentrations corresponding to total suspended solids (PM) were determined by a gravimetric method. The particles were characterized by optical microscopy, scanning electron microscopy (SEM) and electron diffraction analysis X-ray (EDAX). The results obtained showed a direct relationship between the type and quantity of the present particles and the general characteristics of the towns. The present study is part of the research project "Study of the Air Quality in Buenos Aires Province", financially supported by the National Agency of Scientific and Technological Promotion, Argentina.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Ciencias Aplicada

Air quality in Buenos Aires Province, Argentina

Studies of different gaseous contaminants and particulate matter were made in several cities of the Buenos Aires Province in Argentina. These cities have noticeable differences in relation to the number of inhabitants, vehicular density, industrial activities, etc. They are La Plata, Bahía Blanca, Mar del Plata, Pergamino and San Nicolás, among other towns. In each city, continuous monitoring equipment with electrochemical sensor technology was installed, in order to determine the NOx, CO, HC, SO2 and O3 concentration. The particulate matter samples were picked up using high volume equipment and daily concentrations corresponding to total suspended solids (PM) were determined by a gravimetric method. The particles were characterized by optical microscopy, scanning electron microscopy (SEM) and electron diffraction analysis X-ray (EDAX). The results obtained showed a direct relationship between the type and quantity of the present particles and the general characteristics of the towns. The present study is part of the research project "Study of the Air Quality in Buenos Aires Province", financially supported by the National Agency of Scientific and Technological Promotion, Argentina.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Ciencias Aplicada

The Compact Linear Collider (CLIC) - 2018 Summary Report

The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear $e^+e^-$ collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years

A simplicial approach to effective divisors in M¯¯¯¯0,n

We study the Cox ring and monoid of effective divisor classes of M¯¯¯¯0,n≅BlPn−3⁠, over a ring R. We provide a bijection between elements of the Cox ring, not divisible by any exceptional divisor section, and pure-dimensional singular simplicial complexes on {1,…,n−1} with weights in R∖{0} satisfying a zero-tension condition. This leads to a combinatorial criterion, satisfied by many triangulations of closed manifolds, for a divisor class to be among the minimal generators for the effective monoid. For classes obtained as the strict transform of quadrics, we present a complete classification of minimal generators, generalizing to all n the well-known Keel–Vermeire classes for n = 6. We use this classification to construct new divisors with interesting properties for all n≥7⁠

A simplicial approach to effective divisors in M¯¯¯¯0,n

We study the Cox ring and monoid of effective divisor classes of M¯¯¯¯0,n≅BlPn−3⁠, over a ring R. We provide a bijection between elements of the Cox ring, not divisible by any exceptional divisor section, and pure-dimensional singular simplicial complexes on {1,…,n−1} with weights in R∖{0} satisfying a zero-tension condition. This leads to a combinatorial criterion, satisfied by many triangulations of closed manifolds, for a divisor class to be among the minimal generators for the effective monoid. For classes obtained as the strict transform of quadrics, we present a complete classification of minimal generators, generalizing to all n the well-known Keel–Vermeire classes for n = 6. We use this classification to construct new divisors with interesting properties for all n≥7⁠

Equations for point configurations to lie on a rational normal curve

The parameter space of n ordered points in projective d-space that lie on a rational normal curve admits a natural compactification by taking the Zariski closure in (P-d)(n). The resulting variety was used to study the birational geometry of the moduli space (M) over bar (0,n), of n-tuples of points in P-1. In this paper we turn to a more classical question, first asked independently by both Speyer and Sturmfels: what are the defining equations? For conics, namely d = 2, we find scheme-theoretic equations revealing a determinantal structure and use this to prove some geometric properties; moreover, determining which subsets of these equations suffice set-theoretically is equivalent to a well-studied combinatorial problem. For twisted cubics, d = 3, we use the Gale transform to produce equations defining the union of two irreducible components, the compactified configuration space we want and the locus of degenerate point configurations, and we explain the challenges involved in eliminating this extra component. For d >= 4 we conjecture a similar situation and prove partial results in this direction. (C) 2018 Elsevier Inc. All rights reserved

Equations for point configurations to lie on a rational normal curve

The parameter space of n ordered points in projective d-space that lie on a rational normal curve admits a natural compactification by taking the Zariski closure in (Pd)n. The resulting variety was used to study the birational geometry of the moduli space M\u203e0,n of n-tuples of points in P1. In this paper we turn to a more classical question, first asked independently by both Speyer and Sturmfels: what are the defining equations? For conics, namely d=2, we find scheme-theoretic equations revealing a determinantal structure and use this to prove some geometric properties; moreover, determining which subsets of these equations suffice set-theoretically is equivalent to a well-studied combinatorial problem. For twisted cubics, d=3, we use the Gale transform to produce equations defining the union of two irreducible components, the compactified configuration space we want and the locus of degenerate point configurations, and we explain the challenges involved in eliminating this extra component. For d 654 we conjecture a similar situation and prove partial results in this direction

The stable mapping class group of simply connected 4-manifolds

We consider mapping class groups \Gamma(M) = pi_0 Diff(M fix \partial M) of smooth compact simply connected oriented 4-manifolds M bounded by a collection of 3-spheres. We show that if M contains CP^2 (with either orientation) as a connected summand then \Gamma(M) is independent of the number of boundary components. By repackaging classical results of Wall, Kreck and Quinn, we show that the natural homomorphism from the mapping class group to the group of automorphisms of the intersection form becomes an isomorphism after stabilization with respect to connected sum with CP^2 # \bar{CP^2}. We next consider the 3+1 dimensional cobordism 2-category of 3-spheres, 4-manifolds (as above) and enriched with isotopy classes of diffeomorphisms as 2-morphisms. We identify the homotopy type of the classifying space of this category as the Hermitian algebraic K-theory of the integers. We also comment on versions of these results for simply connected spin 4-manifolds. Finally, we observe that a related 4-manifold operad detects infinite loop spaces